# CVE-2026-7851: D-Link DI-8100 yyxz.asp sprintf stack-based overflow

> Remote attackers can trigger a stack-based buffer overflow in the DI-8100 router via the ID parameter, potentially leading to arbitrary code execution.

- **Severity:** High 8.6 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 May 2026
- **Updated:** 6 May 2026
- **Also known as:** GHSA-x4pj-ppv6-g6w7

## What is CVE-2026-7851?

CVE-2026-7851 is a high-severity memory corruption vulnerability in D-Link DI-8100, published on 5 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

A vulnerability was identified in D-Link DI-8100 16.07.26A1. This affects the function sprintf of the file yyxz.asp. The manipulation of the argument ID leads to stack-based buffer overflow. The attack is possible to be carried out remotely. The exploit is publicly available and might be used.

Weakness: CWE-121 (Stack-based Buffer Overflow), CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer)

## Which versions are affected by CVE-2026-7851?

It affects 1 product.


Products: Dlink Di-8100 Firmware.

## How do I fix CVE-2026-7851?

No fix has been published for CVE-2026-7851 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-7851 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-7851 exists.

## Other vulnerabilities in D-Link DI-8100

- [CVE-2025-44083](https://insights.sbomify.com/CVE-2025-44083/): Auth bypass in n/a (critical 9.8)
- [CVE-2026-7853](https://insights.sbomify.com/CVE-2026-7853/): D-Link DI-8100 HTTP auto_reboot.asp sprintf buffer overflow (critical 9.3)
- [CVE-2026-7854](https://insights.sbomify.com/CVE-2026-7854/): D-Link DI-8100 POST Parameter url_rule.asp url_rule_asp buffer overflow (critical 9.3)
- [CVE-2026-7248](https://insights.sbomify.com/CVE-2026-7248/): D-Link DI-8100 CGI Endpoint tgfile.htm tgfile_htm buffer overflow (critical 9.3)
- [CVE-2026-7855](https://insights.sbomify.com/CVE-2026-7855/): D-Link DI-8100 HTTP Request tggl.asp tggl_asp buffer overflow (high 8.7)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-7851 and fix it if it is affected.

What it is: CVE-2026-7851 is a high-severity memory corruption vulnerability in D-Link DI-8100, published on 5 May 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-7851 exists.

Affected product: D-Link DI-8100. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-7851/ (Markdown: https://insights.sbomify.com/CVE-2026-7851/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-7851
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-7851
- OSV: https://osv.dev/vulnerability/CVE-2026-7851

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-7851/
Summaries are generated and may contain mistakes; the official description above is the record.